[GRASS-user] Duplicate vector removal

[Andre Hauptfleisch]

Thanks for the reply Martin. I thought it might have something to do with
the category values.

I know it is easier said than done, but isn't there a way one can skip the
category merger part? Or can I merge all the lines into a single category?
My system doesn't require the use of category values.

I would like to automate the process. At the moment I have a raster image
with some lines in them. I convert these to a vector layer, clean it up a
bit and output it to svg.

Regards,
Andre



On Nov 20, 2007 2:03 PM, Martin Landa <landa.martin at gmail.com> wrote:

> Hi,
>
> 2007/11/20, Andre Hauptfleisch <ahaupt at gmail.com>:
> > Good day,
> >
> > I used the v.clean approach to snap some vectors to each other. This
> caused
> > a number of vectors to lie on the same line. The rmdupl option does not
> seem
> > to remove these short segments.
> >
> > Any ideas on how I can get rid of them? Or perhaps I'm just using
> v.clean
> > wrong. Here is the command:
> >
> > v.clean input=scene01 at test output=scene01_clean type=line
> > tool=snap,rmdupl,rmsa thresh=15 --overwrite
>
> rmdupl removes only *identical* features, for example
>
> L  2 1
>  594233.1875  4921026.59375
>  596956.11875847 4921515.74307787
>  1     1
> L  2 1
>  596956.11875847 4921515.74307787
>  599775.5     4922022.21875
>  1     2
> L  2 1
>  594233.1875  4921026.59375
>  599775.5     4922022.21875
>  1     3
> L  2 1
>  595793       4918172.46875
>  603426.125   4919400.40625
>  1     4
> L  2 1
>  595793       4918172.46875
>  603426.125   4919400.40625
>  1     5
>
> after rmdupl
>
> L  2 1
>  594233.1875  4921026.59375
>  596956.11875847 4921515.74307787
>  1     1
> L  2 1
>  596956.11875847 4921515.74307787
>  599775.5     4922022.21875
>  1     2
> L  2 1
>  594233.1875  4921026.59375
>  599775.5     4922022.21875
>  1     3
> L  2 2
>  595793       4918172.46875
>  603426.125   4919400.40625
>  1     5
>  1     4
>
> First two lines 'lie' on the third one, but they are not identical, if
> you want to remove them, you need to merge them first. E.g.
>
> v.edit dupl1 tool=merge cat=1,2
>
> remove vertex from line
>
> v.generalize in=dupl1 out=dupl2
>
> and then run v.clean.
>
> The result is
>
> L  2 3
>  594233.1875  4921026.59375
>  599775.5     4922022.21875
>  1     1
>  1     2
>  1     3
> L  2 2
>  595793       4918172.46875
>  603426.125   4919400.40625
>  1     5
>  1     4
>
> Martin
>
> > Thanks!
> >
> > --
> > Groete,
> > Andre Hauptfleisch
> >
> > M: 082 5722 469
> > F: 086 687 1106
> > E: ahaupt at gmail.com
> > _______________________________________________
> > grass-user mailing list
> > grass-user at lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/grass-user
> >
> >
>
>
> --
> Martin Landa <landa.martin at gmail.com> * http://gama.fsv.cvut.cz/~landa<http://gama.fsv.cvut.cz/%7Elanda>*
>



-- 
Groete,
Andre Hauptfleisch

M: 082 5722 469
F: 086 687 1106
E: ahaupt at gmail.com
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